1. Field of the invention
The present invention relates in general to electrochemical cells, and more particularly, to an electrochemical cell having an electrode with a modified surface layer. The present invention is further directed to a process for fabricating the same.
2. Background Art
Lithium based electrochemical cells have been known in the art for several years. Furthermore, experimentation associated with lithium based cells having intercalation type electrodes has been explored. While batteries utilizing intercalation type electrodes have exhibited some promising performance characteristics, compatibility between the active material layer of such electrodes and associated electrolyte remains largely problematic. For example, electrochemical cells based on lithiated transition metal oxide electrodes de-intercalate lithium ions at relatively high potentials in order to utilize their full capacity--above approximately 4 volts. This high charge voltage coupled with the naturally oxidizing character of the active material facilitates decomposition of the associated electrolyte. Such decomposition of the electrolyte, among other things, adversely affects coulombic efficiency, decreases net capacity as well as increases self-discharge rates of the cell.
It is therefore as object of the present invention to provide an electrode structure and associated fabrication process that remedies, among other things, the aforementioned detriments and/or complications associated with intercalation type electrodes.